Broken pipes, such as sewer pipe, has traditionally been repaired by excavating the area surrounding the sewer pipe and replacing the damaged section. This is a very expensive and labor intensive solution, and is also an inconvenience to residents living in the area and utilizing roadways overlying the area. An alternative method repairs the pipe in situ, without the site excavation of the traditional method. These “cured-in-place” systems typically utilize a resin coated liner which is inserted into the existing sewer pipe line and fitted against the interior of the sewer pipe. Such methods have been used very successfully for many years, as exemplified by Wood (U.S. Pat. No. 4,009,063); Wood (U.S. Pat. No. 4,064,211); Wood (U.S. Pat. No. 4,366,012); and Taylor (U.S. Pat. No. 5,927,341).
These patent typically envisaged long, straight lengths of main pipes will be lined, but do not address sections containing side or branch pipes. When a lining is applied along a main sewer as described, the tubular structure will cover the lateral connections and these subsequently have to be reopened by the cutting away of coupons of the rigid lining in register with the lateral connections. In many cases it is the connection between the main pipe and branch pipe which causes the greatest problem, as the joint is weak due to the method of initially forming the branch and the difficulty in repairing the joint.
The present invention seeks to provide a method to install cured-in-place liner which addresses the difficulties existing at present.